Sarah our young baby-sitter

Horny Trucker and Young Sarah Part 1
This story is fantasy.
I’m a white male in my 40s and my wife is a cute Asian in her late 40s. We have a great sex life and are swingers. Mostly we like MFM and small gangbangs, she is increadably horny and I love watching her with other men.
My wife and I adopted a adolescent girl from an Asian country about a year ago. This cut back some on our partying but we still managed to play once or twice a month. When we do go out one of her friends has a 13 year old daughter that we hire to babysit. Sarah is a beautiful girl, 5′ tall with a swimmers build. She has long slender limbs and is just starting to get boobies and a touch of curve to her hips. From the time she was ten she seemed to show an attraction to me in a slightly sexual way that I pretended to not see. She would give me long hugs pushing her little bumps of boobies into me, or sit in ways that I could see up her skirt or on her back in a chair and spread her legs so I could see up the leg of her shorts. Her mom would see this and admonish her with “Sarah, sit like a lady”.
One time recently when she was sitting for us I noticed my thumb drives in my desk drawer had been moved (she uses our desktop guest account). I keep some of the pictures from our group sex and such on them. When I drove her home that night (I usually do so the wife can rest, she is tired and needs a shower. We rarely require condoms so she always smells like a cum bucket) she seemed fidgety and ackward until I asked her if something was on her mind.